Hobson, A.J., Stewart, D.I., Bray, A.W., Mortimer, R.J.G. ORCID: 0000-0003-1292-8861, Mayes, W.M., Rogerson, M. and Burke, I.T., 2017. Mechanism of vanadium leaching during surface weathering of basic oxygen furnace steel slag blocks: a microfocus x-ray absorption spectroscopy and electron microscopy study. Environmental Science & Technology, 51 (14), pp. 7823-7830. ISSN 0013-936X
|
Text
Pubsub9071_Mortimer.pdf - Published version Download (6MB) | Preview |
Abstract
Basic oxygen furnace (BOF) steelmaking slag is enriched in potentially toxic V which may become mobilized in high pH leachate during weathering. BOF slag was weathered under aerated and air-excluded conditions for 6 months prior to SEM/EDS and μXANES analysis to determine V host phases and speciation in both primary and secondary phases. Leached blocks show development of an altered region in which free lime and dicalcium silicate phases were absent and Ca–Si–H was precipitated (CaCO3 was also present under aerated conditions). μXANES analyses show that V was released to solution as V(V) during dicalcium silicate dissolution and some V was incorporated into neo-formed Ca–Si–H. Higher V concentrations were observed in leachate under aerated conditions than in the air-excluded leaching experiment. Aqueous V concentrations were controlled by Ca3(VO4)2 solubility, which demonstrate an inverse relationship between Ca and V concentrations. Under air-excluded conditions Ca concentrations were controlled by dicalcium silicate dissolution and Ca–Si–H precipitation, leading to relatively high Ca and correspondingly low V concentrations. Formation of CaCO3 under aerated conditions provided a sink for aqueous Ca, allowing higher V concentrations limited by kinetic dissolution rates of dicalcium silicate. Thus, V release may be slowed by the
Item Type: | Journal article | ||||
---|---|---|---|---|---|
Publication Title: | Environmental Science & Technology | ||||
Creators: | Hobson, A.J., Stewart, D.I., Bray, A.W., Mortimer, R.J.G., Mayes, W.M., Rogerson, M. and Burke, I.T. | ||||
Publisher: | American Chemical Society | ||||
Date: | 19 June 2017 | ||||
Volume: | 51 | ||||
Number: | 14 | ||||
ISSN: | 0013-936X | ||||
Identifiers: |
|
||||
Divisions: | Schools > School of Animal, Rural and Environmental Sciences | ||||
Record created by: | Linda Sullivan | ||||
Date Added: | 13 Sep 2017 14:11 | ||||
Last Modified: | 09 Oct 2017 08:59 | ||||
URI: | https://irep.ntu.ac.uk/id/eprint/31591 |
Actions (login required)
Edit View |
Views
Views per month over past year
Downloads
Downloads per month over past year